Spinneret for the manufacture of rayon



April 23, 1935.. G. M. ALLEN SPINNERET FOR THE MANUFACTURE OF RAYON Filed. March 25, 1935 INVENTOR v GEORGE M. ALLEN BY HIS ATTORNEYS SPINNER/ET FOR THE MANUFACTURE OF RAYON George Morrison Allen, Ridley Park, Pa., assignmto The Viscose Company, Marcus Hook, Pa., a corporation of Pennsylvania Application March 25, 1933, Serial No. 662,751

3 Claims.

This invention relates to a spinneret or spinning nozzle for the manufacture of rayon, and

more particularly to spinnerets used in the cellu-.

lose acetate process of making rayon. One object of the invention is to produce an improved spinning nozzle which is capable of withstanding the high pressures of cellulose acetate spinning without distortion and which at the same time can be formed of metal sufficiently thin to facilitate drilling or punching of the necessary small holes.

is also highly desirable to have the outer face of the spinneret proper of one piece, i. e., clear of all obstructions or joints, in order that this surface may not readily foul and may according easily be wiped clean. In a spinning nozzle made to this invention the outer surface or face of the spinneret is one piece and flat, and the face is suported internally at all points except the immediate hole area.

Other advantages of the invention will appear as the details are described.

In the drawing, Fig. 1 is a vertical section through a spinneret and attachments made in accordance with the invention Fig. 2 is a plan View of the spinneret through which the spinning dope is forced;

Fig. 3 is a plan view of the supporting plate;

while Fig. 4 is a vertical section through a modified form of spinneret and supporting plate.

In spinning acetate rayon it is desirable to extrude the dope or spinning solution through a large number of very small holes.

For example,

of 50 mils or more.

In order to form the small holes with a reasonable degree of accuracy and speed it is desirable to construct the face of the spinneret of metal not exceeding about 15 mils in thickness.

make this One object of this invention is to possible.

In the drawing the spinneret proper is in the form of an inverted cap 5 with the flange 6 resting on the inside of a retaining nut l and the crown projecting downwardly through the opening in the nut and the face 2i lying even with the lower side of the nut or projecting slightly beyond.

Between the retaining nut and the flange of the spinneret is a washer 8 to make the connection tight. The retaining nut is screwed to a threaded base 9, but between the base and the flange of the spinneret is supporting means in the form of a plate .Hl. This supporting plate has a thick rim l I separated from the spinneret by another washer it. he plate and spinneret thus are held together between the retaining nut and the threaded base. The spinning solution is brought to the spinneret through a central opening in the threaded base and a circular series of large holes in the supporting plate. The small holes E5 in the spinneret are arranged in a circle close to the outer edge of the face of the spinneret, as can be seen in Fig. 2.

To assist the central area of the face of the spinneret in withstanding the high pressure of the spinning solution, a post It is soldered, welded or otherwise affixed to the inner face of the spinneret and connected to the supporting disk g tends outwardly to a position close to the circle of holes in the face of the spinneret. It W111 therefore be observed that the face of the spinneret is strengthened and supported on both sides of the circle of holes and close to the holes without obstructing the smooth outer face 2! of the spinneret.

The spinneret itself may be constructed of any of the noble metals, such as platinum or gold and their alloys, or even of such suitable common materials as nickel, stainless steel, monel, and the like. When constructed according to this invention the thickness of the metal can be made much less than the usual 50 mils, for example, 15 mils or even less. By the use of such thin metal construction the cost of a precious or noble metal spinneret becomes economically practical. The noble metals possess many desirable qualities, such as fine grain structure, workability, capacity for taking and holding a high polish, and chemical inertness.

What I claim is:-

l. A spinneret for spinning rayon or the like comprising a cup-shaped member having a flat perforated exposed surface and an annular flange, a perforated plate engaging said flange and formthe bottom of the spinneret and to said supporting plate.

3. A spinneret for spinning rayon or the like comprising a cup-shaped member having a bottom provided with holes arranged near the outer edge thereof and providing a flat exposed surface, in combination with a supporting plate and a post connecting said plate and the inner face of the central area of said bottom for supporting the surface.

GEORGE MORRISON ALLEN. 

